The present invention relates to an oil-mist filter for removing oil mist in a gaseous fuel, for example, utilized for an automobile using CNG (compressed natural gas) as gaseous fuel.
In an automobile using CNG (compressed natural gas) as gaseous fuel, the CNG fills a bomb, as high-pressure gas, mounted to the automobile. Various impurities such as oil lubricating a compressor at a time of charging gas are dissolved in the CNG. The CNG in the bomb is highly pressurized, so that the CNG is reduced in pressure to a constant pressure value through a regulator (pressure reducing valve), and thereafter, the thus regulated CNG is supplied to an engine. In the process of reducing the pressure of the CNG through the regulator, there causes a phenomenon that oil mist dissolved in the CNG is precipitated in a fine foggy state. In order to eliminate an inconvenience that such oil mist adheres a valve portion or injector of the engine of the automobile when driven, an oil-mist filter is utilized.
In a conventional art, there is known an oil-mist filter such as one united with a regulator by being inserted directly into the regulator or one disposed in a duct arranged between the injector and the regulator and having an element therein.
The CNG is filled up with hydrocarbon such as propane, butane or the like for adjusting a quantity of heat at a low temperature time. Such hydrocarbon is seldom precipitated as a liquid component at the time of pressure reduction. In an oil-mist filter having a conventional structure, it is possible to remove the oil mist but impossible to separate the liquid component having low viscosity.
Moreover, since conventional oil-mist filter is formed by cutting a solid material, it has a heavy weight and it is difficult to be assembled, thus increasing a manufacturing cost. Furthermore, for the oil-mist filter disposed in a duct, it is required to independently install IN and OUT ducts, also providing a troublesome disadvantage.
Then, the present invention aims to provide an oil-mist filter capable of removing oilmist and separating liquid component having low viscosity.
Another object of the present invention is to provide an oil-mist filter having a light weight and improved assembling property and hence being manufactured at a reduced cost,
Hereunder, the present invention will be described. Further, it is to be noted that in the following description, although reference numerals described on the drawings accompanied are added with parenthesis, the present invention should not be defined to one described in the drawings. In order to remove the oil mist as well as to separate the liquid component having low viscosity, the inventor conceived an oil-mist filter having an inner two-staged structure in which a fine oil mist is captured by an upper filter element and the upper stage is supported by a supporting member disposed at a lower stage, and the liquid having low viscosity generated at a time of pressure reduction is separated by forming a space below the filter element.
That is, the invention in order to achieve the above objects, is an oil-mist filter provided with a container (1) and a filter unit (8) disposed inside the container (1) so as to filtrate gaseous fuel, the filter unit (8) comprising:
a filter element (9) disposed at an upper stage of the container so as to capture an oil mist; and
a support member (10), disposed at a lower stage of the container (1) below the filter element (9), which supports the filter element (9) and through which the gaseous fuel passes,
wherein a space is formed below the filter element (9)
According to this invention, the oil mist contained in the gaseous fuel is captured by the filter element during the passing through the filter element disposed at the upper stage of the filter unit. The liquid component in the gaseous fuel is once reserved at the lower portion of the filter element disposed at the upper stage, then flows down along the support member at the lower stage by its weight and, thereafter, is stored in the space formed below the filter element. The gaseous fuel, from which the oil mist and the liquid component have been removed, passes through the support member and is supplied to the engine. Further, since the filter element disposed at the upper stage can be supported by the support member disposed at the lower stage without suspending it from the upper portion, a pressure proof strength can be properly ensured. Preferably, the support member (10) is provided, at an outer periphery thereof, with a substantially cylindrical punched plate (24) to which a number of punched holes 24a, - - -) are formed, the punched plate (24) having an outer diameter which is substantially coincident with an outer diameter of the filter element (9)
According to this invention, the liquid component in the gaseous fuel passing through the filter element flows along the outer periphery of the support member with high efficiency and is then stored in the space formed below the filter element. On the other hand, the gaseous fuel passing through the filter element is supplied to the engine through a number of punched holes formed to the support member.
The invention is, for achieving the above objects, an oil-mist filter provided with a bottomed cylindrical container (1) having one end, in an axial direction, opened, an end plate (2) provided at one end of the container (1) and formed with a gas flow-in port (3) and a gas flow-out port (4), and a filter unit (8) disposed inside the container (1) so as to filtrate a gaseous fuel,
the container (1) being formed by press-forming a plate member, the filter unit (8) comprising: a filter element (9) disposed at an upper stage of the container (1) so as to capture an oil mist; and a support member (10), disposed at a lower stage of the container (1) below the filter element (9), which supports the filter element (9) and through which the gaseous fuel passes, wherein a space is formed below the filter element (9)
According to this invention, from the reason mentioned above, the oil mist can be removed and, as well, the liquid component having low viscosity can be separated. Furthermore, since the oil-mist filter can be formed as a disposal cartridge type as an existing oil filter for an engine, the oil-mist filter can be formed with light weight and with high assembling performance, thus being suitable for mass-production and capable of reducing cost. In addition, since the oil-mist filter can take an outer configuration similar to that of the existing oil filter, the oil-mist filter can be removed by using the same jig or tool as that used for the existing oil filter, thus improving maintenance performance. Still furthermore, since the oil-mist filter can be directly mounted to an intake manifold (spin-on structure), as the existing oil filter, at a portion near an injector for an engine of an automobile, for example, it is not necessary to arrange IN and Out ducts.
Furthermore, the invention is, for achieving the above objects, an oil-mist filter provided with a bottomed cylindrical container (1) having one end, in an axial direction, opened, an end plate (2) provided at one end of said container and formed with a gas flow-in port (3) and a gas flow-out port (4), and a filter unit (8) disposed inside the container so as to filtrate a gaseous fuel,
the container (1) being formed from a resin material,
the filter unit (8) comprising: a filter element (9) disposed at an upper stage of the container so as to capture an oil mist; and a support member (10), disposed at a lower stage of the container (1) below the filter element (9), which supports the filter element (9) and through which the gaseous fuel passes, wherein a space is formed below the filter element (9)
According to this invention, the oil mist can be removed by the reasons mentioned above, and in addition, the liquid component having low viscosity can be also separated. Moreover, the oil-mist filter can be constructed as a disposal cartridge type as like as an existing oil filter of an engine.